android-handler

问题 Is a Handler a Thread or not? If yes, how can we update the UI from this Handler(thread)? If we use the Looper concept, it may be possible. In this case, does it apply to any threads? I am very much confused about these Threads, Handlers and Loopers. Could anyone please explain them with an example? Is a Handler a Thread or not? If yes, how can we update the UI from this Handler(thread). If we use the Looper concept, it may be possible, in this case does it apply to any threads? I am very

问题 I want to create multiple handler and run-able when my app receive response from server. The handlers can be maximum 4 and minimum 1. Problem Actually i want to divide cell screen in different part and after dividing i need to display different type of data in all parts of the screen. And in these parts, Each part have multiple items to display. e.g! User want to divide screen in two parts part one contains a video, image and again a video. (3) item in part one part two contain image and a

问题 I want to create multiple handler and run-able when my app receive response from server. The handlers can be maximum 4 and minimum 1. Problem Actually i want to divide cell screen in different part and after dividing i need to display different type of data in all parts of the screen. And in these parts, Each part have multiple items to display. e.g! User want to divide screen in two parts part one contains a video, image and again a video. (3) item in part one part two contain image and a

问题 I want to parcelable a Handler object to send it by a Bundle from one Activity to a service in order to get some info from this service. Right now, to test it it's a simple message. Here's the code in the Activity: private MyHandler mHandlerSharing = new MyHandler() { public void handleMessage(Message msg) { // this line in the Activity is never reached when debugging String data = msg.getData().getString("data"); Toast.makeText(mContext, data, Toast.LENGTH_SHORT).show(); } }; // in some

问题 I was trying to build some sort of sequential countdown. Meaning, that I build up a queue of "exercises", each one containing a specific duration, which is the countdown time. In a custom Countdown class, I pop these exercises off the queue and use the duration as countdown. I want these countdowns to run one after another. For this I built a Countdown class, based on the code basis of the abstract class CountDownTimer . import java.util.ArrayDeque; import java.util.ArrayList; import java

问题 My app is composed of a single Activity . In this activity, I'm creating multiple HandlerThread s which run in a loop to do socket blocking operations. Currently I post a quit message to everyone of these HandlerThread s during my Activity.onDestroy() . Sometimes, when I open my app, close it and relaunch it, it crashes (many time due to posting a message to a handler thread which is not running). My question is: What is the right way to close HandlerThread when I close my app? (Note that

问题 Could someone explain me different situations to use AlarmManager vs Handler with examples please. Any disadvantages of using these two as alternate to each other? Thanks. 回答1: They have little to do with one another. I am assuming you are referring to using something like postDelayed() on Handler for polling, which is but one small feature of Handler . You would use postDelayed() (also available on any widget or other subclass of View ) in an activity for simple timing events that are within

问题 I am new to android and i try to develop a system but when i finish code the handler show this warning below show the code after I edit, the handler in event ontounch show the warning handler cannot be resolved. I try putting // to ignore the handler at i try run the application and its result in force close. public class MainActivity extends Activity { protected static final int STOP = 100; ImageView iv; private ProgressBar pb; LinearLayout ll; private AnimationDrawable anim; ScrollView sv;

问题 I have wrote a service to log accelerometer values in background. The idea is to register for sensor listener and write the values to storage. I have enabled the StrictMode.enableDefaults() in the MainActivity of the app (not in the service) to check if the service runs on its own thread. But it does not! I don't know what is the problem...I have this AsyncTask class that I hoped to take care of the problem but it apparently did not (this is inside the service and its execute method is called

问题 I use the code below for getting some work done everytime after some time interval, and using post delay in 'finally' clause and oustide of runnable. Here is the code. Runnable runnable = new Runnable() { @Override public void run() { try { // do somthing } catch (Exception e) { // TODO: handle exception } finally { handler.postDelayed(this, 60000); } } }; handler.postDelayed(runnable, 60000); handler.postDelayed(runnable, 60000); will run two times or a single time. 回答1: it depends! first